Belgium's Prince Amedeo and Princess Elisabetta have welcomed their third child into the world

Alongside a picture of the baby, the Belgian Royal Palace tweeted: "Prince Amedeo and Princess Elisabetta are delighted to announce the birth of their daughter Alix. She was born in Brussels on Saturday 2 September, weighs 3.4 kg and, like her mother, is doing well. Their families share in this great happiness."

Although Alix will be ninth in the line of succession to the Belgian throne, she will not be titled Princess but instead will be known as Archduchess Alix of Austria-Este.

Her father, Amedeo, who is the eldest son of Princess Astrid and the first grandchild of former King Albert and Queen Paola, is sixth in the order.

King Philippe currently holds the Belgian throne and he will be succeeded by Princess Elisabeth, who will be the nation's first-ever female ruler by birth thanks to legislation passed a decade before she was born, which meant a daughter wouldn't be overtaken in the line of succession in favour of a younger male sibling.

Three years ago, the Princess began preparing for life on the throne by starting her military training at Brussels' Royal Military Academy.

She said in a speech to mark her 18th birthday: "These 18 years have been filled with many rewarding moments that have made me the person I am today.

"[It is] a step that I take with great optimism. I realise that I still have a lot to learn. I will also focus on that in the coming years: trying to understand the world better - and helping to improve it, by giving the best of myself.

"The country can count on me."